Crossing the Board
by the moon and the stars
Summary: His voice grazed her ear like a knife. "It's a dangerous game you're playing, Shadowhunter, but make no mistake. Only one of us is a pawn, and it isn't me." / A desperate Isabelle seeks help from an unlikely source—and gets more than she bargained for. Post-2x07. Two shot.
1. En Passant

**Crossing the Board**

 **Summary:** His voice grazed her ear like a knife. "It's a dangerous game you're playing, Shadowhunter, but make no mistake. Only one of us is a pawn, and it isn't me." / A desperate Isabelle seeks help from an unlikely source—and gets more than she bargained for. Post-2x07. Two shot.

 **Disclaimer:** Nothing recognizable belongs to me.

 **A/N:** Basically, 2x08 speculation. Better late than never, I guess. Enjoy.

* * *

 **I.** _ **En Passant**_

Crossing the threshold, his attention immediately swept to the patron nursing an empty glass at the corner of the bar. In this dark underbelly of downtown Brooklyn she stood out like a beacon, especially given those telltale runes marring otherwise flawless skin. Sparing her from being easy pickings for this dive's less scrupulous characters.

She carried on tracing the rim of her glass as though unaware, or at least uninterested. But her back stiffened long before he crossed her periphery.

"A bit far from the Institute, aren't you?"

Brown eyes alighted in recognition. "Of all the gin joints."

"I believe that's my line, considering this is a vampire hot spot you're slumming." Leaning against the bar, his eyes leveled an accusation. "Of which I'm sure you're well aware."

She shrugged away a curtain of ebony hair. "Maybe I felt like broadening my horizons."

"Or avoiding recognition," he parried. "Tough luck, there."

Her mouth thinned, ever so slightly. "And you? You don't strike me as the social butterfly type."

"I conduct business here, on occasion."

"All work and no play? Sounds boring."

"Does a Shadowhunter know anything else?"

"Wouldn't you like to know." Blood-red lips relaxed, curving an invitation. He stared back, unmoving, and she sighed. "You can sit, you know. I don't bite."

"I can't say the same."

"Yeah?" She arched a delicate brow. "Is that a threat or a pickup line?"

"Whichever one is less flattering to your ego." He bent his face away, scanning the room for nothing in particular. "I'm not looking for company."

"Don't tell me you're still sore about that hole I blasted through the Hotel Dumort. If you ask me, it really… brightened up the room. Plus, Camille's back under lock and key now, so might as well let bygones be bygones." A pause, and then soft laughter baited his attention. "Typical vampire. So alpha, holding onto grudges for eternity. You should relax. Have fun… if you even know how."

He studied the way her empty glass still fell victim to one idle hand; the hem of her fitted dress, the other. A portrait far more telling than any verbal repartee.

He chose his next words carefully. "In retrospect, you stealing Camille from my custody did have one upside, at least. Finally gave me an excuse to… _disinvite_ that incompetent fledgling from my clan. Kid's been nothing but a grade-A pain in my ass since he turned."

"Saving Simon's bacon has become a recent habit of mine," she sympathized. Leaning forward, she glanced at him from beneath thick lashes. "You can thank me for cutting that cord by buying my next drink."

"Will it bring this conversation to a close?"

"Only one way to find out."

And because he didn't end stalemates with surrender, he signaled for the bartender. Claimed the adjacent seat. Didn't so much as blink.

Not even when she flashed a winning smile—a mask as fixed as his own.

* * *

She stumbled through the night, her heavy heels at war with the uneven pavement and the fire in her veins. Close. So close.

"Who knew Nephilim were such light weights?" It toed the line between annoyance and amusement, stopping just shy of the latter.

She glanced sideways. "You know, a gentleman would offer a lady his arm, at least."

"Neither of those descriptors is accurate." But he obliged her request, however reluctant. "You're hardly in any shape to discuss business," he observed, "which could have been done inside, like civilized people."

"This doesn't require an audience."

"You realize there's a reason I frequent that place, don't you? Everyone there is plied on half-priced shots. Plus, the noise is enough to drown out any… delicate information being exchanged."

The only noise she cared to drown out was the blood singing in her ears. By contrast, the alley they approached was quiet, even by New York standards. For a spell, it threw everything into sharp, alarming clarity.

Suddenly her arm dropped like lead. Her companion rounded on her. "Okay. We're alone. Talk."

But apparently she'd left rational thought behind several cocktails ago. She didn't talk. Didn't think. Just moved.

Fingers tangled in the lapels of his jacket and _pulled_.

The response was immediate, as though he expected the attack, but his mouth was as cold and unyielding as hers was feverish. Deliberately she fused both hands to his chest—a gesture of goodwill. Assurance that she wasn't surreptitiously reaching for a weapon.

He gave no such quarter.

Her tongue had barely scraped the tip of a fang when he spun her around, pinning her against a brick wall. Had she been a mundane, it would have knocked the wind from her.

She gasped when he dipped his head. Arched her neck, waiting. Wanting.

But felt only a breath of soft laughter. Then a voice grazing her ear like a knife. "It's a dangerous game you're playing, Shadowhunter, but make no mistake. Only one of us is a pawn, and it isn't me."

She scoffed, even as her pulse hammered against the flimsy guise of composure. "This isn't entrapment, Santiago. No breech of the Accords. In case you haven't noticed, you have my permission."

"But not mine."

Three innocuous, sobering words.

He pulled away just enough that his pale face took up her entire field of vision. She catalogued the unblinking gaze. Even breath. Not one gelled hair out of place. A predator in his element—odd, given the rejection.

"You want something," he stated with certainty. "And you're vain enough to think you can get it for free. I'll tell you what I told Camille the first and only time she attempted the same ploy: Get over yourself."

The comparison left her fuming. Had he struck her, it would have been kinder. "Whatever. Your loss."

"For the record, playing hard to get only works when you're actually _hard to get_." His iron grip still formed a cage around her, but it wasn't brute force that rooted her to the spot. "The signs were easy enough to read. You're jonesing. Badly. I could smell it on you the second I walked into the bar."

She inhaled sharply. "Yin fen?"

"Desperation." His eyes narrowed, swallowing darkness. "How long has it been?"

She didn't answer.

"Silence won't win you any favors tonight," he warned. "Neither will more lies."

"Almost three days." The admission stole the last of her restraint. "Look, I got an… anonymous tip that your people might have what I need. Is it true?"

A beat of silence, and then he released her. She sagged against the wall, practically boneless. "What do you think the Head of the Institute would say now if he saw one of his elite in such pathetic shape?"

"Who do you think got me hooked in the first place?"

Instant gratification: genuine surprise rippled across his features. "Is that so?"

"Can you help me or not?" she snapped. She was ready to explode out of her skin. If only she possessed the energy.

"Oh, I can," he assured her. "But you'll owe me."

"Fine. Whatever it costs. Who's your source?"

But he just stared at her, waiting. Impatient.

Without warning her knees buckled, and brick scraped skin as she slipped lower and lower down the slope. Something was wrong. Withdrawal was strong, but never this powerful before. Even aided by alcohol.

Her head snapped up as something clicked into place. As darkness peeled away the edges of her vision.

"How are you feeling?" Not concern. Mild curiosity, at best.

"What's happening? What did you do?" A garbled string of syllables, as though her voice had traveled from far away. In vain she struggled to summon the whip from her wrist. "What are you doing to me?"

"Helping." For the first time, he sounded unmistakably amused. As far from placating as possible. Part of her wondered if she should, or even could, feel fear. "Isn't that what you wanted?"

Oblivion stole whatever answer she might have given. But not before she heard the thundering echo of distant laughter.

* * *

 _ **En passant**_ —a special maneuver in chess where a pawn is captured "in passing" by an opposing pawn. A rule added to prevent pawns from having too much power or freedom. [credit: chess dot com]

* * *

 **A/N:** Apologies for the lazy scene setting and general lack of editing. I _really_ wanted to get this posted before 2x08 aired… well, at least before I watch it, which won't be until tomorrow. Second part should hopefully be up around then.


	2. Queening

**A/N:** Taking a little artistic license here (though not intentionally) with regard to the properties of yin fen. Since I haven't yet read The Infernal Devices, where it apparently originates, I'm just going off the TV show (which is a separate universe anyway) and giving it my own spin. Just heads up.

* * *

 **II. Queening**

"Magnus, open up. Package delivery."

Recognizing the summons, the warlock crossed his apartment to answer.

On the other side of the door stood his most recent patient. Bearing his next, unconscious.

Magnus sighed. "Dear Izzy. I'd hoped I was wrong." To her would-be rescuer, he added, "Careful. Cross the threshold carrying her like that, and in some cultures you'd be married."

Heedless, the newcomer breezed past him and made a beeline to the nearest couch, where he unceremoniously dropped his cargo. Magnus frowned. "Well, then. I guess the honeymoon's over."

"My debt's repaid." The announcement was brusque, but not unexpected. "Though your choice of favors is, as always, peculiar."

"You know very well there's no debt between two old friends, Raphael." The door closed with a flourish of his hand, and Magnus joined his guest in the living room. "But if it makes you feel better to think of it that way, I won't quibble over semantics. I will thank you for getting her here safely, though."

A shrug, rippling across an immaculately pressed suit. "You provided the not-so-anonymous tip about vampire venom. And the sleeping draught—that was a nice touch, by the way. Shadowhunters are much more tolerable when they're compliant."

"Normally I wouldn't resort to such unseemly methods, but yin fen is extremely dangerous. Couldn't risk waiting. Plus, turnabout's fair play." Though he derived no pleasure from it whatsoever. "I suspected she wasn't being honest when I last spoke with her. What I didn't know," he added, darkly, "was how far off the path she'd strayed. How far down the rabbit hole this all goes."

"It was Victor Aldertree, Magnus. Her dealer."

"Aldertree?" The warlock was aghast. "The Head of the Institute? The one who—"

"Filleted my face for Intel on Camille? That's the one."

At the reminder, fury burrowed deep in Magnus's gut—even hotter than back then, without fear to temper it. "First he's torturing Downworlders," he thought aloud, "and now he's enslaving the minds of his own people? To what end?"

But his companion only shook his head. "You're the one with ties to the Shadowhunter community. I suggest you warn them what their boss is up to."

It was, perhaps, the last thing he expected to hear. "Why, Raphael, is that a hint of compassion I detect?"

"Sentimentality is your crutch, Magnus, not mine. To me, they're nothing more than brute soldiers. Cannon fodder."

Magnus sensed the unspoken. "And?"

"And I play for the long game." The vampire cut a glance to the slumped form beside them, and it didn't escape notice that his eyes were without hunger. "I don't know what Aldertree's endgame is, but I do know Valentine's. Death to our kind. There's a war coming. I don't care much for Nephilim—can't stand them most of the time—but we need every player on the board. Even pawns."

Oddly, the denouncement elicited a smile. "We're all pawns at one point or another, Raphael. How quickly you forget that even the lowliest one can rise to become queen. One just has to cross the board first."

Magnus watched his former protégé, whose face was awash with a slideshow of memories. History that made contradiction impossible. Guarded by a character that made concession improbable.

So it came as no surprise when the next move was towards the exit. "Well, when that happens, be sure and let Her Majesty know that I'll be in touch."

"What for?"

Raphael paused at the doorframe just long enough to toss over his shoulder: "That's another difference between us, Magnus. When someone owes me, I collect."

Then he disappeared into the night.

* * *

Isabelle awoke with a jerk, wincing as she sat up. She could feel every ray of sunlight stabbing through her eyes to the back of her skull. When the blindness slowly retreated, she looked around, hunting for clues.

Her surroundings had only just become clear when a voice at her side chirped, "Good morning, and welcome to Saint Magnus's Home for Wayward Shadowhunters, where freeloaders come for the lukewarm service and stay for the complete lack of housing alternatives."

"Magnus? What—?" She shook her head. "How did I get here?"

He rounded the corner of the couch and looked down at her. "A word to the wise? Don't accept drinks from strange men in seedy bars."

The implication dispelled the last of the fog in her brain, and her mouth fell open. "You had that vampire _roofie_ me? Magnus, how could you?"

"I believe that's my line," he countered. "Considering your recent extracurricular activities, it's a bit late to claim the moral high ground. How long?"

Isabelle exhaled. Didn't bother pretending to misunderstand. "Over three days now."

"Not your last fix. I mean," he sidled closer, "how long have you been sneaking around like a common drug addict? Lying to everyone?"

She bristled at the accusation. "Look, it's not what you think. I just needed to take the edge off after I got wounded by the demon that attacked the Institute. But I'm fine now. It's fine. Under control."

"Enough. You've already lied to my face once." Her chin snapped up. It was the first time she had seen Magnus furious. "Don't me wrong, I'm used to lies. From most people, in fact. But not from you. And what's worse is you've made me an unwitting accomplice in your deception. I don't like keeping things from your brother, Isabelle. I can't imagine you do either."

"You're not going to tell him, are you?"

"And let you off the hook? Not a chance. Besides," he tacked on, "I can assure you, you have much bigger worries right now."

"Like what? Another lecture?" She rose from the couch, teetering slightly in last night's skyscraper heels. "What is this, anyway? Some kind of one-on-one intervention? Did everyone else forget to RSVP?"

"You're lucky Jace is off gallivanting with his current flavor of the hour, or else I imagine it would be a full house in here. As it is, you only have to deal with me for the moment."

But she was already marching past him. "I think I'll pass. I don't need—"

She stopped cold, just before the door. It wasn't until then that she understood the severity of her situation. The magnitude of her disadvantage. Hadn't even seen it coming. More than anything else, that ignorance scared her.

"Magnus," her voice was low, taut, "where the hell is my stele?"

"Nowhere you will find. Same goes for your whip. Don't worry, you'll get them back when this is over. Follow me," he bade her. "I have something to show you."

Isabelle seethed. With all the freedom of a rat in a maze, she trailed after him.

When she caught up, Magnus spoke again. "As I'm sure you've discovered on your own, your _iratze_ rune is useless against yin fen. As is my magic. I did, however, give you something that should alleviate at least a fraction of the withdrawal symptoms. You're welcome. Ah. Here we are."

They halted at the end of the hall in front of an open doorway. Curious, Isabelle peaked inside.

Then looked back at her host, missing the point entirely. "It's just a guest room."

"It's _your_ room," he corrected.

"My—what?"

Magnus rattled his knuckles against the solid doorframe. "Soundless. Impervious. Wards strong enough to contain a rampaging elephant. And with a touch of modern décor because, well, who says a makeshift panic room needs to look like a sanatorium?" Then his voice turned truly grim. "Only cure is to wait for the toxin to leave your system entirely. In other words, the only way _out_ ," he swept an arm past the threshold, "is _in_."

She couldn't help it. She laughed—a terrible sound that bordered on hysteria. "You're mad at me enough to take me prisoner?"

"Don't be dramatic, Isabelle. And don't deflect. There's no vendetta here, no conspiracy. I'm doing what needs to be done. For _you_."

"You're insane if you think I'll agree to this."

"You know, I was going to toss you in there while you were unconscious, but I decided to give you a choice. Either you reclaim your honor and your dignity and go in of your own volition… or I really will toss you in myself."

When he raised a hand, she glared at the ominous purple sparks dancing across his fingertips. "Yeah, some choice."

"Yes, well, we're a bit past the hand-holding stage. Straight to tough love, sweetheart."

"Love?" she sneered. "You're only doing this because I'm Alec's sister. You don't give a damn about me."

Magnus stared at her mildly, as though she were nothing more than an unruly pet in need of discipline. "If it helps, then by all means. Continue raging at me all you like. Again, nothing I'm not used to. Though I should warn you: You think you don't like me now, you're in for a rude awakening. These next few days will be… very unpleasant."

 _Days?_

The verdict lanced her heart, short-circuited her nerves. A distant part of her knew she was in a no-win standoff.

But every instinct, every ounce of training refused to submit.

"Wait a second," she realized. "Max's Rune Ceremony. It's tonight."

"I know. Who do you think is throwing the party?"

"I have to be there for my brother, Magnus. My family—"

"Sorry," though he didn't sound the least bit apologetic. "But I'm afraid nothing in the world can spare you Maryse's wrath now. At least this way, you'll be spared the Clave's."

"Look, just—just let me attend the ceremony, and then I'll come back," she reasoned. "I'll come straight back and turn myself over to you. I promise."

"That's the yin fen talking." The warlock's hand fell, but the rest of him was utterly unmoved. "A charming devil, but the problem is I've learned not to trust it." Then he smiled. "But this is good. We've reached the bargaining stage. Progress."

"I'm strong enough," she argued. "I can make it through tonight. Just tonight, Magnus. Please."

"And now we've circled back to denial." Exhaustion chipped away at his marble countenance. "Look, this is happening. The sooner you accept that, the better… at least, you should be in seventy-two hours. Give or take."

"They'll never forgive me." Part threat, part plea, with the same effect as all the rest.

"Better to ask for forgiveness when you're _you_ , Isabelle, and not the person you're in danger of becoming."

It was both the most horrible and most honest thing she'd gotten from him.

It was too much.

She didn't think. Just moved. Threw herself across the border between freedom and captivity. Between surrender and control. She hardly knew anymore which side was which.

Without looking back, she uttered, "Don't expect a thank you."

"I never do. That's the thing I've learned about helping people: They so very rarely thank you for it. I've made my peace with that. In time," compassion reached across the chasm, "I hope you find yours."

It gave her just enough strength to keep her head held high when the door closed, sealing her fate.

Because for that brief moment, she recalled a feeling more addictive, more powerful than any drug.

 _ **Fin**_

* * *

 **Queening—** refers to a specific type of "pawn promotion" in chess where a pawn becomes a queen once it crosses the board and reaches the eighth rank i.e. the furthest point into opponent territory. [credit: chessburst dot com]

* * *

 **A/N:** There you have it. Poor Izzy, I really put her through the ringer. Here's hoping she kicks this habit ASAP. And with that, I'm off to (finally) watch the new episode. Thanks for reading.


End file.
